Apparatus for concentrating materials, such as coal



Oct. 4. 1921. 1,644,112

E. DEISTER APPARATUSVFOR OONCENTRATI N G MATERIALS SUCH AS COAL Filed Nov. 28. 1924 s Sheets-Shut 2 g I w "Fig.

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Y APPARATUS- rox conczuranmc uuu'snnns suca AS COAL Filed Nov. 28. 1924 v 3 Sheets-Sheet 3 1 (I VENTOR. $11111 De/5hr (Ar-q Zl. ZOLZ ATTORNEY.

Patented Oct. 4, 1927.

EMIL nnrsran; or Form warm a, mourn.

APPARA'II TS FOR CONCENTRATING MATERIALS, SUCH AS GOAL.

Application filed November 28, 1924. Serial 1W0. 752,600.

The invention relates to dry concentrating tables of the difierentially reciprocated, transversely inclined type whereon stratification of the materials is accomplished by air 5 under pressure.

It is a Well recognized fact that, when particles of matter of about the same size but of different density fall through quiescent air, those particles of greatest density attain a greater velocity than those of less density. Therefore, when the particles come to rest some stratification of the same occurs-the heavier particles being at the bottom, the next lighter next above, etc. Also, if two particles of matter of about the same shape and density but of different sizes fallthrough quiescent air the larger particle will attain the greater velocity since the resistance of the air is proportional to the crosssectional area of the particle and such resistance is proportionally greater on the smaller particle.

Prior dry concentrating tables for concentrating ore, cleaning coal, sizing and separating comm'inuted materials, etc), have been constructed with pervious surfaces on I their decks through which air under pressure ascends, together with impervious channels in the surfaces. The material to be sized or separated is passed over these surfaces. The ascending air tends to float the materials and stratification thereof on ltlfie surface and in the channels follows. lighter particles settle with the heavier particles in the channels and travel with the latter in the channelsunder the influence of the reciprocating movement of the table. The lighter particles pass over the sides of the channels as the bed of materials in the 40 channels increases in depth or the channel decreases in depth. To accomplish this flotation and stratification, however, air under considerable pressure is required and careful previous sizing of the material is essential so that each particle shall about .the samecross-sectional area. The separation of the material on the table is, therefore, relatively slow and incomplete and its capacity is relatively small. I have found that a dry concentrating table is more efficient and a cleaner conticles are not only rendered buoyant but are propelled by air'under pressure toward the edge of the table at which they are todischarge, and the object of my invention is have v centrate is obtained when the lighter parto provide a reciprocating, transversely inclined table by which the materials to be concentrated are caused to cascade down the transverseslope thereof and subjected to lateral jets of air under pressure which maintain a constant positive transverse movement of the lighter particles toward the intended discharge point therefor, the heavier particles being collected in channels and conveyed off the table by the longitudinally reclprocating movement of the table.

Another. object is to provide a reciprocating, longitudinally channeled table with means whereby air under pressure is caused to pass transversely through the channels for agitating the materials caught therein and causing the upper strata thereof to move laterally. therefrom while the heavier partlcles are conveyed in the channels under the influence of the reciprocating movement of the table.

Another object of my invention is to provide an eflicient transversely inclined dry concentrating table with novel means on the surface of its deck by which the materials are caused to travel over a series of clifi's or precipices extending longitudinally along the transverse slope of the deck and gentle jets of air are caused to pass laterally through the falling particles at each preclpice for effecting a stratification of the same andcausing the lighter particles to move down the said slope.

An embodiment of the invention is illustrated in the accompanying drawings in which Figure 1 is a plan view of a table embodying the invention; Fig. 2 a side-elevat onal view of the same; Fig. 3 a cross-section on line 33 of Fig. 1; Fig. 4 an enlarged cross-section on line 4-4 of Fig. 1;

Fig. 5 a fractional view of the surface of the deck taken in the direction of the arrow in Fig. 4; Fig. 6 a bottom plan view of a fraction of one of the air channel forming members; Fig. 7 a side Y view of the said member, taken in the direction of the arrow in Fig. 6; Fig. 8 a cross-section similar to Fig. '4 illustrating a modified form' of riflie and pervious deck; Fig. 9 a side view of the same taken between and in the direction of the arrows in Fig. 8; Fig. 10 a plan view of one of the air channel forming strips of Fig. 8; Fig. 11 a side view ofv the strip and Fig. 12 a vertical cross-section of one of the supports forthe table.

' causing it to differentially reciprocate longitudinally, a spring 7 opposing the rearward movement of the deck.

The deck'is preferably hollow the base 8 being horizontal transversely and the two relatively steep sides 9 and IQ sloping downwardly in opposite directions from their junction to the base 8. T The base 8 isimpervious and a conduit 111 to which air under pressure is supplied is connected by the flexible conduits 12 to the deck by which the an under pressure is supplied to the an box within the deck'and formed by the base. 8,

' the two sloping sides 9 and 10 and by suit able end members, 8.-

The sides 9 and 10 form the top of the deck of the table. The two top sections are alike in construction except that the parts of one are arranged in reverse order to that of the other since the sectlons slope in opposite Y directions. Each section is formed of a series of parallel ribs 12, Fi 4, extending from. v the head or notion en 13 of the table toward the foot or discharge .end 14. The outer portion of eachrib is triangular in cross-section, and secured to the upper surface of said triangular portion is a series of corrugated strips 15 extending alon the rib. Preferably, these strips are forme of rubber, such as stair-tread material, and each strip is so cut thatv the corrugations are diagonal relatively to the lengthof the strip, as shown in Fig. 6,so that when the strips are in position the ducts 16 therein are diag onal to the line of reciprocation of the table,

In Figs.3 and 4 the approximate. inclination of the surface of the deck is shown and in Fig. 4 the parts are in substantially full size. The inner ends of the ducts communica'te, through the spaces between the ribs, with the air box and hence cause the air to discharge from the air box in jets oblique to the line of reciprocation of the table asshown by the arrows in Figs. 1 and 4:, and since the slope of the top surface of the deck is relatively steep the jets approach thehofi'lizontal in the operating positionof the ta e.

A strip '17 on the'top of the series of corrugated strips is suitably secured to the. v.rib below it, .and it may be secured to, the

next rib above against which it abuts. This strip may have any desired shape or form,

V which for a secured. An angle bar a number of forms of the same being illustrated in Fig. 4. The top faceof each strip forms one side wall 18 of a channel A that extends from the head end of the table toward the discharge end 14 and the outer face of the rib together with the corrugated strips forms the other side wall 19 of the channel, the said side wall being pervious in its upper ortion. Each channel is oblique to the line of reciprocation of the table-+it extends u wardly on the transversely sloping top oft e 'deck. I

In order to save air and to cheapenthe construction of the table I attach a high board or guard 20 at each lower rear corner of the dec the board extending from a suit-- able 0; selected point in the head end to the dischar 'e-side 21, and I close off the triangular section 22, rearward of the board so that no air will pass through it. A board 23 extends along the ridge of the deck and high boards or guards 24 extend down the oppositely declined surfaces of the deck from a selected point in said ridge board to the dis-v charge ends Id, at suitable points above the.

lower forward corners of the deck. The boards 24 hold back or .buck the materials. The triangular spaces 25' are impervious and perform no function. They could be omitted ut the table is more economical and convenient to build with them than without them.

The channels A terminate at the high guards 24 and at the lower portion of the discharge ends 14.' Someof the channels beginat the head end of the deck, others at the boards 20 and still others at the discharge sides 21. c

In the modified form shown in.'Fig. 8, great many uses is the preferred form, the corrugated'strips 25 are separated by wooden strips 26 and each is secured on the upper face of a rib 27, the uppermostwooden strip being engaged on the outer face of the next rib above. The outer edges of thestrips are flush with the outer face of the ribs upon which they are I. 28 of suitable mate! rial s secured to the up ermost wooden strip and to the rib above and forms the bottom of a channel that is oblique to the line of reciprocation of the table. As in the previously upwardlyextending wall is pervious, since the oblique chamiels 29 form ducts that com municate with-the air box and outside air. Theoutwardly projecting arm of each'angle series of strips described form-of channel, av portion of its member 28 may overhang the pervious wall of the channel.

The table is supported so that its transversely sloping'sides also slope downwardly longitudinally toward the discharge ends 14. The materials to be treated are fed through a hopper 30 that is disposed over the ridge board adjacent to the head end-of I deck. The travel down the slope along the high boards the table. They are deposited onto both declined top surfaces and under the influence of gravity tend to travel down each slope toward the discharge sides 21. The materials drop or cataract over the pervious walls of the channels in succession and as they fall the jets of air at each channel are projected obliquely and laterally through the sheet of materials, carrying the lighter particles to the rim of the precipice below. The heavier particles settle into the channel. As the materials continue their cataracting movement down the slope, more and more of the heavier particles are caiwht in the channels and which under the induence of the differential movement of the table'are conveyed in the channels toward the forward ends of the same. As the channels fill up the up er strata escape over the sides thereof and fall over the precipices, more and more of the lighter particles being advanced down the transverse slope of the heavier particles 24 and pass 01f the table at the discharge ends 14:, and the lighter particles, such as coal, eventually reach the discharge sides 21 of the table andleave the table at those 1 sides.

One wall of each channel being more or less pervious, the collecting of the lighter particles in the channels is avoided, since the jets of air are. directed through the upper strata of the materials that collect in the channels.

In practice the channels and the precipices will be disposed on the deck at a suitable angle to the direction of reciprocation of the table. The diagonal arrangement of the same shown in the drawings is preferable since it affords a large capacity for the table. I

It will be seen that the operating portion of each top surface of the deck consists of a series of longitudinal -steps, the treads of which are impervious and the risers of which are perforated, the tread and a portion of the riser above forming a channel.

Various arrangements and constructions of the parts constituting the deck will be suggested to one skilled in the art, the construction and arrangement shown being only illustrative of the invention.

What I claim is: v

1. A dry concentrating table comprising a differentially reciprocated, transversely inclined deck, means to feed material to be concentrated to thedeck, an air box within the deck for air under pressure, a series of channels in the transversely inclined surfaceof the deck extending longitudinally thereof and corrugated strips in one wall of each channel which form ducts communicating with the air box and leading laterally therefrom to the exterior, said wall also formeventually laterally therefrom to the exterior, said wall also forming the abrupt wall of a precipice contiguous to the channel next above.

3. A dry concentrating table comprising a differentially reciprocated, transversely inclined deck, means to feed material to be concentrated to the deck, an air box within the deck for air under pressure, a series of channels in the transversely inclined surface of the deck extending longitudinall thereof in a direction oblique to the line 0 reciprocation of the deck, and corrugated strips in one wall of each channel which form ducts communicating with the air box and leading laterally therefrom to the exterior, the ducts being oblique to the longitudinal axes of the strips, said wall also forming the abrupt wall of a precipice contiguous to the channel next above.

4. In a dry concentrating table a deck consisting of a transversely inclined frame,

. a plurality of longitudinally disposed ribs on the frame one below and laterally spaced from another, superimposed corrugated strips extending between the upper side of each rib and the other side of the rib above, means to feed material to be concentrated upon the upper side of the deck, means to impart longitudinal movement to the deck and means beneath the said ribs to cause a gaseous medium under pressure to discharge through the laterally perforated means;

5. In a dry concentrating table a deck consisting of a transversely inclined frame, means to reciprocate the frame longitudinally, a plurality of laterally perforated, upwardly extending walls formed of corrugated strlps supported on the frame the inner face of the upper portion of each wall contacting with the outer face of the lower portion of the wallabove and'the upper surface of each wall cooperating with the lower portion of the wall above to form a channel, means to supply a gaseous medium under pressure rearwardly of the walls, and means to feed material upon the deck, the perforations in the walls having-communication with "the gaseous medium and being adapted to conduct the same laterally through said walls and laterally through the upper portion of the channels.

6. In a dry concentrating table a transversely inclined deck, means to reciprocate the deck longitudinally, the surface of the deck being formed in a series of longitudinal steps arranged at an angle to the direction of reciprocation of the deck, the treads of the steps being impervious and the risershaving a plurality of lateral ducts extending diagonally through the same and an air box beneath the said surface to which 10 air under pressure is supplied, means to feed material to be concentrated uponthe deck, the material under the influence of gravity being caused to descend over the steps and the ducts being adapted to direct the air under pressure laterally through the descending-niaterial for' moving the lighter particles laterally therefrom.

In witness whereof I have hereunto subscribed my name.

EMIL DEISTER. 

